Recently, core biopsy devices have been combined with imaging technology to better target a lesion in breast tissues. One such commercially available product is marketed under the trademark name MAMMOTOME™, by Ethicon Endo-Surgery, Inc. An embodiment of such a device is described in U.S. Pat. No. 5,526,822 issued to Burbank, et al., on Jun. 18, 1996, and is hereby incorporated herein by reference. Its handle receives mechanical and electrical power as well as vacuum assist from a remotely positioned control module that is spaced away from the high magnetic field of a Magnetic Resonance Imaging (MRI) machine.
As seen from that reference, the instrument is a type of image-guided, percutaneous coring, breast biopsy instrument. It is vacuum-assisted, and some of the steps for retrieving the tissue samples have been automated. The physician uses this device to capture “actively” (using the vacuum) the tissue prior to severing it from the body. This allows the sampling of tissues of varying hardness. In addition, a side opening aperture is used, avoiding having to thrust into a lesion, which may tend to push the mass away, cause a track metastasis, or cause a hematoma that, with residual contrast agent circulating therein, may mimic enhancement in a suspicious lesion. The side aperture may be rotated about a longitudinal axis of the probe, thereby allowing multiple tissue samples without having to otherwise reposition the probe. These features allow for substantial sampling of large lesions and complete removal of small ones.
In the aforementioned Pub. No. US 2003/0199785 to Hibner et al., localization fixtures are described that are attachable to a breast coil. These localization fixtures aid in accurately positioning the probe to a location of a suspicious lesion within breast tissue. In particular, the X-Y-Z Cartesian coordinates of a suspicious lesion are referenced to a fiduciary marker in the localization fixture. Humanly visible measurement guides for each axis then allow the probe to be correspondingly positioned after a patient has been withdrawn from a closed bore MRI machine without the need for imaging the probe during insertion. In addition, the localization fixture enables use of a detachable probe of an MRI biopsy device. Thus, during subsequent reimaging of the probe, a handle of the MRI biopsy device may be detached, as may be necessary within the close confines of a closed bore MRI machine. When the handle is attached to the probe, various support structures of the localization fixture are described that support the extended length of the handle.
While a localization fixture used with a detachable MRI biopsy probe has a number of advantages, it would be desirable to incorporate additional features that further assist in accurately positioning the probe, preventing over insertion or inadvertent retraction of the probe, and supporting the MRI biopsy device.
Consequently, a significant need exists for an improved localization fixture for in an MRI guided biopsy procedure that assists in locating a suspicious lesion and for accurately performing a biopsy or complete removal of the suspicious lesion, even in conjunction with the close confines of closed bore MRI machines.